I try generate cert for my internal server with next domain that include real domain name.
My domain is:
I ran this command:
certbot certonly --standalone --preferred-challenges http -d server1.realdomain.com
It produced this output:
Failed authorization procedure. server1.realdomain.com (http-01): urn:acme:error:connection :: The server could not connect to the client to verify the domain :: DNS problem: NXDOMAIN looking up A for server1.realdomain.com
The following errors were reported by the server:
To fix these errors, please make sure that your domain name was
entered correctly and the DNS A/AAAA record(s) for that domain
contain(s) the right IP address. Additionally, please check that
your computer has a publicly routable IP address and that no
firewalls are preventing the server from communicating with the
client. If you’re using the webroot plugin, you should also verify
that you are serving files from the webroot path you provided.
My web server is (include version):
The operating system my web server runs on is (include version):
CentOS Linux release 7.4.1708
My hosting provider, if applicable, is:
I can login to a root shell on my machine (yes or no, or I don’t know):
I’m using a control panel to manage my site (no, or provide the name and version of the control panel):
Can I create cert for my server?